Sergienko, G.

Resource type

Text

Abstract [en]

Stereoscopic fast camera observations of pre-characterized carbon and tungsten dust injection in TEXTOR are reported, along with the modelling of tungsten particle trajectories with MIGRAINe. Particle tracking analysis of the video data showed significant differences in dust dynamics: while carbon flakes were prone to agglomeration and explosive destruction, spherical tungsten particles followed quasi-inertial trajectories. Although this inertial nature prevented any validation of the force models used in MIGRAINe, comparisons between the experimental and simulated lifetimes provide a direct evidence of dust temperature overestimation in dust dynamics codes. Furthermore, wide-view observations of the TEXTOR interior revealed the main production mechanism of intrinsic carbon dust, as well as the location of probable dust remobilization sites.

Vignitchouk, Ladislas

KTH, School of Electrical Engineering (EES), Space and Plasma Physics.

2016 (English)Doctoral thesis, comprehensive summary (Other academic)

Abstract [en]

Plasma-material interaction constitutes one of the major scientific and technological issues affecting the development of thermonuclear fusion power plants. In particular, the release of metallic dust and droplets from plasmafacing components is a crucial aspect of reactor operation. By penetrating into the burning plasma, these micrometric particles act as a source of impurities which tend to radiate away the plasma energy, cooling it down below the threshold temperatures for sustainable fusion reactions. By accumulating in the reactor chamber, dust particles tend to retain fuel elements, lowering the reactor efficiency and increasing its radioactivity content. Dust accumulation also increases the risk of explosive hydrogen production upon accidental air or water ingress in the vacuum chamber. Numerical dust transport codes provide the essential framework to guide theoretical and experimental dust studies by simulating the intricate couplings between the many physical processes driving dust dynamics in fusion plasmas. This thesis reports on the development and validation of the MIGRAINe code, which specifically targets plasma-surface interaction processes and the physics of dust particles impinging on plasma-facing components to address long-term dust migration and accumulation in fusion devices.

Place, publisher, year, edition, pages

KTH Royal Institute of Technology, 2016. p. 80

Series

TRITA-EE, ISSN 1653-5146 ; 2016:084

National Category

Fusion, Plasma and Space Physics

Research subject

Electrical Engineering

Identifiers

urn:nbn:se:kth:diva-187638 (URN)978-91-7729-041-4 (ISBN)

Public defence

2016-06-13, E3, Osquars backe 14, Stockholm, 13:30 (English)

Opponent

Pitts, Richard

ITER Organization.

Supervisors

Ratynskaia, Svetlana

KTH, School of Electrical Engineering (EES), Space and Plasma Physics.